Converting Spectrum Games to the CPC

[Jonathan.]

Hi chaps,


I wondered if any of you might be looking for a new challenge but lacking inspiration?

I have a substantial softography of Spectrum games - I started out writing games for magazine covertapes back in 1989 and have been banging them out ever since - and really don't have the time to convert them to other machines.

I know that conversions aren't everyone's thing and that lame Spectrum ports are something of a sore point.  Games designed for one machine don't always work on another.  However, quite a few would work very nicely on the Amstrad and some might be better than the original Spectrum version in the right hands. 

Naturally, I would be more than happy to share my fully annotated source code and provide any assistance I can.

Here are a few games I think would make the transition well, although there are plenty of others for which I haven't found YouTube videos.  There are some unusual game designs here and it would be great to get more people playing them!












The grave obviously needs modifying to say "ZX" in the CPC version. 










Can I tempt anyone with Albatrossity?  If I had more time I'd have a go myself...

[SyX]

Guys, this is a great oportunity, Jonathan's games are crazy and fun, the kind of games that we lack in CPC.

Even his platform games are different of the typical boring ones that are usual those days.

This is not only a call for coders, the forum artists can show us their skills in how to make those games using the best of the CPC graphical capabilities.

And with the original playability of the speccy version plus a little of CPC love in the art department, those original games are going to look brilliant in CPC.

I could take one the next year when i get more free and adding a few PlayCity extras... But come on! I'm sure that i'm not the only one that loves Jonathan's games

[mr_lou]

Do these games run on a ZX Spectrum 48k?

[EgoTrip]

These games are great. But the music is even better. Who did the music on these games?

[SyX]

These games are great. But the music is even better. Who did the music on these games?

A few talented ZX musicians, as Yerzmyey or Gasman from the AY Riders.

[CraigsBar]

A few talented ZX musicians, as Yerzmyey or Gasman from the AY Riders.

Oh yes, Those games look like tremendous fun. I can see a CPC version would need to use Mode 0 with some well drawn graphics (Of similar quality to R-type 128) and ideally with the BGM reproduced from the spectrum original via a PlayCity. Resulting in the fathful reproduction of the tune, leaving the internal AY free for the sound effects.


They could be AWESOME. Such a shame I would not know where to start on any of that so have to rely on the skills of others... Perhaps it could be another New GX4000 Cart proposal (Without the PlayCity obviously, But a plus palette and DMA tunes) a multigame cart consisting of 3 or 4 of those would be great and allow GX4000 owners something new to play - Maybe ever dissuade the image of a Speccy port.


When done correctly and with care they can, after all, be brilliant games.


Craig

[Jonathan.]

They're all 48K games, with AY music for 128K machines.  Matt Westcott and Yerzmyey are fantastic musicians, no doubt about that!

[Gryzor]

These were covertapes? Wow. I'm impressed. That Cybernoid quasi-clone and the mini-golf thingie look like so much fun!

[andycadley]

There are some interesting titles in there, pretty much all of which the CPC is certainly capable of. A few, like Albatrossity, I'm just not sure what a CPC conversion could really add to the game. Some of the others could really take advantage of the graphical boost though (although some of the attribute tricks in Egghead might be a challenge to pull off well).

[SyX]

@andycadley: Well, i think the Jonathan's idea for letting other guys to port his games to CPC, it's mainly, because in this moment he has not enough free time for doing high quality CPC ports himself.

And we can assume that those volunteers are going to do this, starting for using a bigger screen than the typical width of 128/256 pixels (i'm sure that Jonathan will give permission to redesign the levels to use a bigger screen to reduce the border in the CPC version) and even flirting with the CPC+ or PlayCity features.

In other case, there are not reasons for making those CPC ports, because we can always play to the original ZX versions.

For example, for "Albatrossity", i can imagine a version in the line of your magnificent JSW+, using a mode 0 background, rasters, mode 1 sprites, a few extra songs, a more elaborated scoreboard, highscores (and being able to load/save them in floppy), being able to load pack with new levels (i could make an import/export script for tiled, if people thinks the level editor in the game is not friendly enough), adding passwords for playing to higher levels, ...

Maybe i'm too ambitious, but these are the versions that i would like to see

[andycadley]

If someone wanted to give that a go, I'd be very interested to see what they came up with. Personally I can't quite "see" how I'd make it a worthwhile conversion and I think it's important that you can make something that is, if not better, at least "different" enough. As you say, we can all just play the Spectrum originals these days, so a straight copy in Mode 1 is less appealing.

Anyone fancy mocking up some screens of what the other titles might look like on the CPC? Surely there are a few artists who might inspire us coders around here? 

[MacDeath]

Anyone fancy mocking up some screens of what the other titles might look like on the CPC? Surely there are a few artists who might inspire us coders around here?

Sure.



oops... 


jokes appart :
As told, to simply straight-port those game may not be that much interesting on CPC.
The 256x192 sized display looks like a stamp on the CPC, and this may need quite some resize.
To just put into mode0 don't always do the trick, as Mode0 needs more surface on screen to be actually mindblowing looking.

CPc is not supposed to display only 256x192 or 128x192 (mode0).
its natural display would more be something like 320x200/160x200 or 256x256/128x256.
It may even actually go for a 192x256 in mode0 which would be humongous and would need serious code re-design as it would be basically equivalent to four times the amount of Speccy screen weight (not counting the attributes)...

on the other hand, CPC being more heavy per pixel, not sure the big score musics would fit as easily.
And as usual if the games are Speccy48 + music patch for 128K, it can't decently fit on a CPC in 64K RAM.

Albatrossity is a good exemple of game that could use perfectly the PLUS.
As Syx told : Mode0 background, and Hardsprites "mode1" sprites as those sprites are quite simple and wouldn't need too many different animation frames nor be too numerous on screen.

Egghead looks like a nice JetSetWilly alike except it has "pockets" so actually a mix between JetSetWily and Sorcery.
But on CPC it would need a quite complete re-design, not only graphically.

As I told, those speccy games in 256x192 with big HUD (the score zone) look like post-stamps.the cartoonish design needs Mode0, but mode0 needs big screen to look better.
And to manage big screen, speccy code may not be really portable on CPC, need to go many different ways as the amount of datas to handle if quite different for the quite same CPU time.

Many Speccy ports failed hard at life due to the Speccy specification being quite different from the CPC specs, beside having a Z80 and an AY and being both built by amstrad at one point.

Speccy used small resolution screen because it had no choice. so they would compensate with extra scrolling.
When this come to CPC, CPC also has the extra scrolling while it could jsut display bigger and get rid of extrascrolling. example :

Final Fight.


Don't be fooled by the Mode0 on CPC.
this game has a vertical scrolling... on CPC it could simply ignore this ressource-waster extra scroling jsut by displaying "256x256" instead of 256x192... would most probably save some cycles.(or not... lol)

Games like Strider or blacktiger would activate vertical scrolling each time you would jump... they spend all ressource just to try to re-center the sprite so it doesn't go out of the screen, also wasting on rasters probably, and converting 1bpp graphics into 2bpp mode1... but that's another story.
as playfield was quite small indeed due to large HUD and also because it had to fit some 48k or 64k specifications (Speccy48 or CPC464).
so each jump need to compensate by vertical scrolling so you couldn't see where you would land... ouch... simply because they didn't re-size the sprites accordign to playfield to keep a ratio compairable to original game.
Black Tiger arcade doesn't have quite huge display size : 256x224... HUD is overlayed in masked sprites as often in arcade, but sprites are quite small indeed. and the scrolling wouldn't activate at each jump.
horizontally the hero is always at the center, but vertically it would scroll when you land on a platform, be escalating on a pillar or if big freefall.
But compare the playfields :
Arcade : 256x224pixels.
Speccy/CPC : perhaps 200x112 pixels actually.
but sprites almost do have the same size...
This can't be good.



If I remember correctly Switchblade had an interesting comparison/port method between CPC/GX4000 and speccy.

CPC : tiles would be sized 8x8 (or 16x16 actually ?)
Speccy : Tiles would be the same but sized 6x8 (12x16?)... so some part removed...

This enable to put the same level design from 320x200 to 256x192, sort of.



I guess they turned it into monocolour game because of this.
Switchblade is the perfect example of a game that could use some attributes (walls, foreground tiles) but as the tiles weren't sized into the 8x8 it wouldn't have fit.

[SyX]

I totally agree with @andycadley, we have great artists in the forum and a few CPC mockups of those games will help to get inspiration for these projects... for example, i only worked in Pac-Man because the mock ups that TotO made here in the forum

When i look "Albatrossity", i always remember CPC games like Croco Magneto or Ball Bearing, completely different gameplay, but games with very CPCish look:

[andycadley]

I'm not sure i'd want to redesign all the level layouts, I can't think of many examples where that has gone well - the C64 version of Jet Set Willy is really let down by trying to make the screen wider, for example. However doing the "Switchblade" method in reverse could well work. Since none of the games scroll, having a bigger play area shouldn't be a problem and we're not limited by "attribute" or "character size" limitations in the way Speccy/C64 programmers are. We could easily use, say 6*12 Mode 0 pixels for each "character" worth if we wanted. Doing something like that should allow the existing level data and design to carry over and probably won't affect the overall logic of the engine much, allowing an easier port without having to totally rewrite every aspect from scratch.

[TotO]

For a scrolling game, the display area is biggest w/o the need to redesign it.

But compare the playfields :
Arcade : 256x224pixels.
Speccy/CPC : perhaps 200x112 pixels actually.
but sprites almost do have the same size...
This can't be good.

SNES is 256x224... Arcade is 384x224 wide.

[arnoldemu]

And for those who want to show off their graphics skills and who are interested in this, they can do great mock ups with the original art work as the inspiration!

[Axelay]

I'm not sure i'd want to redesign all the level layouts, I can't think of many examples where that has gone well - the C64 version of Jet Set Willy is really let down by trying to make the screen wider, for example. However doing the "Switchblade" method in reverse could well work. Since none of the games scroll, having a bigger play area shouldn't be a problem and we're not limited by "attribute" or "character size" limitations in the way Speccy/C64 programmers are. We could easily use, say 6*12 Mode 0 pixels for each "character" worth if we wanted. Doing something like that should allow the existing level data and design to carry over and probably won't affect the overall logic of the engine much, allowing an easier port without having to totally rewrite every aspect from scratch.

Was thinking along the lines of increasing the 'character' size as well, but there would be a challenge with speed or sprite space if you increase the sprite size in a similar fashion.  Suddenly a 2x2 character sprite frame in your example has grown from 64 bytes to 144! 

[andycadley]

Was thinking along the lines of increasing the 'character' size as well, but there would be a challenge with speed or sprite space if you increase the sprite size in a similar fashion.  Suddenly a 2x2 character sprite frame in your example has grown from 64 bytes to 144! 

True, but I think the relatively simplistic nature of the originals would counter that in many cases. And I'd have no qualms personally about going 128K only if needed to make the conversions worthwhile (heck I'd go 128 Plus only if that was the only way to add real value to them)

[Nich]

Guys, this is a great oportunity, Jonathan's games are crazy and fun, the kind of games that we lack in CPC.

I could take one the next year when i get more free and adding a few PlayCity extras... But come on! I'm sure that i'm not the only one that loves Jonathan's games

I've often wanted to convert more of Jonathan's games, but I just don't have the time to commit myself to it. Area 51 took me a month, and it was only 4K in size on the Spectrum! Jonathan did send me the code for an extended version of the game, but I never got an opportunity to convert it.

[SyX]

@Nich: I hope that you can get more time for our hobby in the future and we can see more of your projects

[Axelay]

True, but I think the relatively simplistic nature of the originals would counter that in many cases. And I'd have no qualms personally about going 128K only if needed to make the conversions worthwhile (heck I'd go 128 Plus only if that was the only way to add real value to them)

True enough for some of them, especially Albatrossity, but I was thinking more of the busier/shootier ones.

[arnoldemu]

I appreciate people want to see amstrad versions that are done good.

My question is: has anyone started yet?

Also: You must learn to walk before you can fly

[SyX]

My question is: has anyone started yet?

I hope that someobody has showed interest and contacted with Jonathan in private.

The task of making new CPC games can not be always in the hands of same 5 or 6 guys, they are very talented, but they are busy with its own projects.

Also: You must learn to walk before you can fly

Sure, but a guy needs to start in some place and this is one of the best chances, even better than the 16 KBs rom compo, he only needs to take the first step... there is not going back after that

Of course, he should not choose "More Tea, Vicar", if it's his first project ... sure Axelay has dips already 

But Jonathan's catalogue has games of every type.  And for those games without scrolling feel free of taking routines from the Pac-man code (or other CPC game with sources published), from the arnoldemu's site and all the CPCwiki posts. And if he has problems, don't desist and ask for help in the forum, ask for help doesn't make you and your project worst, at contrary you will improve your project and when you will release it, everybody will love it

[arnoldemu]

I agree SyX.

Yes converting these games to CPC are perfect for others who are learning to code on CPC.

But there are talks of using Plus or PlayCity, this is fine, but my suggestion is that first make it on CPC without these features (="learning to walk") then update them for playcity and plus ("=learning to fly").

I also hope somebody has already contacted Jonathan and is working on one of these

I am in agreement with you. I want to encourage others to have a go

[TFM]

My question is: has anyone started yet?

No, not me, therefore I shut up here.    But let me put my Drei Pfennig in here... The perfect person/team to care about this funny Speccy games would be someone who alreay has some kind of "Spectrum emulator' regarding the screen output.


The gain of these games should be to do a conversion with few effort. Now this is IMHO: If I would need to put in too much effort, then I would rather do an original new game for CPC.